sodium acsorbate in dimethylsulfoxide-d6; water-d2 byproducts: dipyrido(3,2-f:2',3'-h)quinoxaline; addn. of sodium ascorbate to (AuCl2(dipyrido(3,2-2',3'-h)quinoxaline)(PF6) in small amt. of d6-DMSO; dilution with D2O; pptn., monitoring of soln. by NMR;